Auto mowing system

ABSTRACT

A robotic mowing system that includes a station and a robotic mower. The robotic mower has a controller and a memorizer, the memorizer stores a working procedure, and after receiving a start command input by a user, the controller executes the working procedure, so as to control the robotic mower to automatically and repeatedly mow and return to the station to be charged until the controller receives a stop command. In this way, the user does not need to input working parameters, and costs are relatively low.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/758,424, filed Sep. 2, 2015, which is a national phase entry under 35U.S.C. §371 of International Patent Application PCT/CN2013/090746, filedDec. 27, 2013, designating the United States of America and published asInternational Patent Publication WO 2014/101840 A1 on Jul. 3, 2014,which claims the benefit under Article 8 of the Patent CooperationTreaty and under 35 U.S.C. §119(e) to Chinese Patent Application SerialNo. 201210585225.9, filed Dec. 28, 2012, and Chinese Patent ApplicationSerial No. 201210584509.6, filed Dec. 28, 2012, the disclosure of eachof which is hereby incorporated herein in its entirety by thisreference.

TECHNICAL FIELD

The present disclosure relates to a robotic mowing system.

BACKGROUND

With continuous development of computer technologies and artificialintelligence technologies, a robotic drive device that is similar to anintelligent robot has gradually entered people's lives. Companies suchas Samsung and Electrolux have both developed fully automatic vacuumcleaners that have entered the market. This fully automatic vacuumcleaner is usually of a small size, integrates with an environmentsensor, has a self-drive system, a vacuum system, a battery system and acharging system, can move around indoors on its own without humancontrol, and when power is low, automatically returns to a station,connects to the station to be charged, and then continues to move aroundand perform vacuum cleaning. Meanwhile, companies such as Husqvarna havedeveloped a similarly intelligent mower that can automatically mow auser's lawn and perform charging without involvement of the user.Because this robotic mowing system, once set, needs no effort for latermanagement, the user is liberated from boring and time-consuminghousework such as cleaning and lawn care and, therefore, is greatlywelcomed.

An existing robotic mower is generally applied to a working area with arelatively large size, such as 1000 square meters. When working, theuser needs to input working parameters such as the size of a workingarea and a working time, and the robotic mower stops moving when thoseparameters are achieved. For example, after calculating or estimatingthe size of a working area, the user inputs a value of the area sizeinto the robotic mower, and the robotic mower automatically calculates aworking time required for completing the size, starts a timer, and stopsmoving when the timer reaches the calculated working time. For a workingarea having a relatively small size, such as 50 to 200 square meters,the user still needs to input working parameters to control the workingtime of the robotic mower. In this scenario, it is troublesome, andcosts are relatively high.

Therefore, it is necessary to improve the existing robotic mower andstation so that the user does not need to input working parameters andwhere costs can be reduced.

BRIEF SUMMARY

In view of the shortcomings of the prior art, the present disclosureprovides a robotic mowing system in which a user does not need to inputworking parameters, and costs are relatively low.

The technical solutions of the present disclosure are implemented inthis way:

A robotic mowing system comprises a station 200 and a robotic mower 100,wherein the robotic mower 100 has a controller 110, a memorizer 120, apower source 50 and a drive motor 30. The memorizer 120 stores a fixedworking procedure, and after receiving a start command input by a user,the controller 110 executes the working procedure so as to control therobotic mower 100 to automatically and repeatedly mow and return to thestation 200 to be charged, until the controller 110 receives a stopcommand.

Preferably, the working procedure comprises the following steps:starting the drive motor 30; controlling the robotic mower 100 to entera predetermined working area; controlling the robotic mower 100 to mowaccording to a predetermined route or a random route; detecting power ora discharge time of the power source 50, and if the power of the powersource 50 is lower than a first predetermined value or the dischargetime reaches a first predetermined time, controlling the robotic mower100 to return to the station 200 to be charged; and detecting the poweror a charging time of the power source 50, and if the power of the powersource 50 reaches a second predetermined value or the charging timereaches a second predetermined time, controlling the robotic mower 100to mow again.

Preferably, the robotic mowing system further comprises a physicalboundary apparatus that is configured to form a boundary line to definethe working area, the robotic mower working inside the working area 300.

Preferably, the physical boundary apparatus comprises severalindependent wireless generators that are configured to generate awireless signal as a boundary signal, and the robotic mower 100 isprovided with a wireless receiver that detects the boundary signal.

Preferably, the wireless generator is an infrared generator, and thewireless receiver is an infrared receiver.

Preferably, the robotic mowing system further comprises a virtualboundary apparatus configured to define the working area 300 of therobotic mower.

Preferably, the virtual boundary apparatus, disposed inside the roboticmower 100, is a global positioning module, a photographing module or alawn identification module, the global positioning module performingwireless communication with a positioning satellite, and forming avirtual boundary by using a predetermined position coordinate sequence,the photographing module shooting an image of the robotic mower and thesurrounding area, and delineating a virtual boundary on the image, andthe lawn identification module determines whether the ground is a lawnaccording to a color or dampness of a lawn.

Preferably, the controller 110 controls the robotic mower 100 to returnto the station 200 along a boundary of the working area 300.

Preferably, the controller 110 controls the robotic mower 100 to returndirectly toward the station 200.

Preferably, the station 200 is provided with at least one ultrasonicgenerator, the robotic mower 100 is provided with at least oneultrasonic receiver, so that when the robotic mower 100 goes back, thecontroller 110 adjusts a moving direction of the robotic mower 100according to a receiving condition of the ultrasonic receiver, so thatthe robotic mower returns toward the station 200.

Preferably, the station 200 is provided with the ultrasonic generatorand an infrared generator, the robotic mower 100 is provided with theultrasonic receiver and an infrared receiver, the ultrasonic generatorand the ultrasonic receiver are configured to guide the robotic mower100 to return toward the station 200, and the infrared generator and theinfrared receiver are configured to guide the robotic mower 100 toconnect to the station 200 to be charged.

Preferably, the robotic mower 100 further comprises an operationinterface for a user to operate, the operation interface is providedwith only a power button 150, a start button 130 and a stop button 140.The power button 150 is used for turning the power to the robotic mower100 on or off. The start command is generated when the start button 130is pressed down, and the stop command is generated when the stop button140 is pressed down.

In the present disclosure, at least a part of a boundary of a workingarea is a physical boundary. A robotic mower is provided with a physicalboundary signal generator, a physical boundary signal receiver and acontroller. A first boundary signal is reflected when reaching thephysical boundary. The physical boundary signal receiver receives thereflected first boundary signal, and the controller determines adistance between the robotic mower and the physical boundary. In thisway, no other boundary line needs to be arranged, and costs arerelatively low.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described below with reference to theaccompanying drawings and embodiments:

FIG. 1 is a schematic diagram of working of a robotic mower inside aworking area according to the present disclosure;

FIG. 2 is a schematic block diagram of the robotic mower of FIG. 1;

FIG. 3 is a schematic diagram of the robotic mower of FIG. 1 whenreturning to a station;

FIG. 4 is another schematic state diagram of the robotic mower of FIG. 3in a process of returning to a station;

FIG. 5 is a schematic diagram of a robotic mowing system according tothe present disclosure;

FIG. 6 is a schematic exploded diagram of the robotic mower of FIG. 5;

FIG. 7 is a schematic block diagram of the robotic mower of FIG. 5;

FIG. 8 is a schematic flowchart of a working procedure of a roboticmowing system according to the present disclosure; and

FIG. 9 is a schematic diagram of another embodiment of a robotic mowingsystem according to the present disclosure.

DETAILED DESCRIPTION

Referring to FIG. 1, a robotic mower 100 is configured to move and mowin a predetermined working area 300. A station 200 is provided insidethe working area 300 or at a boundary of the working area 300, and isconfigured to recharge the robotic mower 100 when the robotic mower 100is short of power and goes back to be charged, or to provide a shelterfrom rain or a stop for the robotic mower 100.

At least a part of the boundary of the working area 300 is a physicalboundary, such as a fence 302, a wall 304 or a wall of a house 306. Inthis embodiment, the physical boundary forms most of the boundary of theworking area 300.

Referring to FIG. 2, the robotic mower 100 includes a housing (notshown), several wheels (also not shown) that are disposed at the bottomof the housing, at least one drive motor 30 that is configured to drivethe wheels, a cutting blade 42 (see FIG. 6) that is used for cutting, acutting motor 40 that is configured to drive the cutting blade 42, apower source 50 that supplies power to the drive motor 30 and thecutting motor 40, a controller 110, a physical boundary signal generator160 and a physical boundary signal receiver 170.

The controller 110 is connected to the drive motor 30, the cutting motor40, the power source 50, the physical boundary signal generator 160 andthe physical boundary signal receiver 170.

The physical boundary signal generator 160 and the physical boundarysignal receiver 170 are configured to sense the physical boundary of theworking area 300. When the robotic mower 100 is close to the boundary,the controller 110 controls the robotic mower 100 to change its movingdirection and to return to the working area. In this embodiment, thewheels have a left drive wheel and a right drive wheel. The drive motor30 includes a left drive motor and a right drive motor. The left drivemotor is configured to drive the left drive wheel, and the right drivemotor is configured to drive the right drive wheel. The controller 110controls the left drive motor and the right drive motor to rotate atdifferent rotation rates, so as to control the robotic mower 100 tochange the moving direction to return to the working area.

The physical boundary signal generator 160 is configured to generate afirst boundary signal. The first boundary signal is reflected whenreaching the physical boundary. The physical boundary signal receiver170 receives the reflected first boundary signal. After the physicalboundary signal receiver 170 receives the reflected first boundarysignal, the controller 110 determines whether the robotic mower 100 isclose to the physical boundary.

Further, the controller 110 stores a predetermined distance value. Whenit is calculated that a distance value between the robotic mower 100 andthe physical boundary is greater than the predetermined distance value,the controller 110 keeps the moving direction of the robotic mower 100unchanged. When it is calculated that the distance value between therobotic mower 100 and the physical boundary is less than or equal to thepredetermined distance value, the controller 110 determines that therobotic mower 100 is close to the physical boundary and controls therobotic mower 100 to change its direction, preventing the robotic mower100 from crashing into the physical boundary, enabling the robotic mower100 to remain within the working area 300.

Specifically, the first boundary signal is an ultrasonic signal, thephysical boundary signal generator 160 is an ultrasonic generator, andthe physical boundary signal receiver 170 is an ultrasonic receiver. Thecontroller 110 calculates a distance between the robotic mower 100 andthe physical boundary according to a time difference between generatingand receiving the ultrasonic signal.

The first boundary signal may also be a laser signal, the physicalboundary signal generator 160 is a laser generator, and the physicalboundary signal receiver 170 is a laser receiver. The controller 110calculates a distance between the robotic mower 100 and the physicalboundary according to a time difference between generating and receivingthe laser signal. A handheld laser rangefinder that integrates thephysical boundary signal generator 160 and the physical boundary signalreceiver 170 may be used, which has a detection range within 200 m, plusor minus 2 mm.

The first boundary signal may also be a boundary infrared signal, thephysical boundary signal generator 160 is a first infrared generator,and the physical boundary signal receiver 170 is a first infraredreceiver. Because attenuation of the boundary infrared signal is strongin a propagation process, when being relatively far from the physicalboundary, the first infrared receiver cannot effectively identify theboundary infrared signal. In addition, a user may set, according toneeds, a distance at which the first infrared receiver identifies theboundary infrared signal. For example, after the boundary infraredsignal is generated and returns for a predetermined distance, intensityof the boundary infrared signal reduces to a predetermined intensityvalue. When intensity of the reflected boundary infrared signal thatreaches the first infrared receiver is greater than or equal to thepredetermined intensity value, the first infrared receiver identifiesthe boundary infrared signal. In this case, the controller 110determines that the robotic mower 100 is close to the physical boundary,and controls the robotic mower 100 to change its direction.

Referring again to FIG. 1, a part of the boundary of the working area300 is a virtual boundary, and has no physical boundary, such as anentrance of a courtyard, that is, there is an opening 320. The virtualboundary is provided with at least one virtual boundary signalgenerator, and the robotic mower 100 is provided with a virtual boundarysignal receiver. The virtual boundary signal generator generates asecond boundary signal. After the virtual boundary signal receiverreceives the second boundary signal, the controller 110 determines thatthe robotic mower 100 has reached the boundary.

In this embodiment, the virtual boundary signal generator is a radiofrequency identification (“RFID”) tag 330, and the virtual boundarysignal receiver is a radio frequency reader 340. At least one radiofrequency identification tag 330 is disposed at the opening 320, and theradio frequency reader 340 is disposed at the bottom or a side surfaceof the housing of the robotic mower 100, and is configured to generate afirst radio frequency signal. When the robotic mower 100 is close to theradio frequency identification tag 330, the radio frequencyidentification tag 330 receives the first radio frequency signal andgenerates a second radio frequency signal. When the radio frequencyreader 340 receives the second radio frequency signal, the controller110 determines that the robotic mower 100 has reached the boundary.

The virtual boundary signal generator may also be a metal marker, suchas a metal strip 350, and the virtual boundary signal receiver is ametal detector 360. At least one metal strip 350 is disposed at opening320 along a direction of the boundary. The metal detector 360 isdisposed on the robotic mower 100, and is configured to detect the metalstrip 350. The metal detector 360 has an oscillator circuit (not shown)that is configured to generate an electromagnetic induction signal. Whenthere is metal existing around the metal detector 360, the metalgenerates electromagnetic induction and an eddy current is generated, sothat power consumption of the oscillator circuit in the metal detector360 increases, and oscillation weakens and even stops. Change of theoscillation is detected and converted into a light signal or a soundsignal, so that whether the metal strip 350 exists may be detected. Whenthe metal detector 360 detects the metal strip 350, the controller 110determines that the robotic mower 100 has reached the boundary.

In another embodiment, the virtual boundary signal generator may also bea magnet (not shown). The virtual boundary signal receiver is a magneticsensor (also not shown) that is configured to sense a magnetic fieldgenerated by the magnet. When the magnetic sensor detects the magneticfield of the magnet, the controller 110 determines that the roboticmower 100 has reached the boundary.

In this embodiment, the controller 110 further detects residual power ofthe power source 50. When the residual power of the power source 50 islower than a certain value, the controller 110 controls the roboticmower 100 to return to the station 200 to replenish power.

In this embodiment, at least one metal strip 350 is connected to thestation 200, and is disposed in parallel to the physical boundary. In aprocess in which the robotic mower 100 returns to the station 200, thecontroller 110 first controls the robotic mower 100 to move along theboundary of the working area 300 in a predetermined direction, such asin a clockwise or counterclockwise direction. When the robotic mower 100is close to the station 200, the metal detector 360 detects the metalstrip 350, and the controller 110 controls the robotic mower 100 to moveforward along the metal strip 350 and to connect to the station 200. Inanother embodiment, the metal strip 350 may also not be parallel to thephysical boundary.

The station 200 is provided with a return signal generator that isconfigured to generate a return signal. The robotic mower 100 isprovided with a return signal receiver that is configured to receive areturn signal. The controller 110 controls the robotic mower 100 to movetoward the return signal generator, so as to enable the robotic mower100 to return to the station 200.

Referring to FIGS. 3 and 4, the return signal generator includes a firstultrasonic generator A, a second ultrasonic generator B and a secondinfrared generator C. When the robotic mower 100 returns to the station200, the controller 110 adjusts a moving direction of the robotic mower100 according to the condition of the receiving signals of the firstultrasonic generator A and the second ultrasonic generator B, so thatthe robotic mower 100 returns directly toward the station 200. When therobotic mower 100 is close to the station 200, the controller 110controls the robotic mower 100 to keep receiving a return infraredsignal of the second infrared generator C, so that the robotic mower 100connects to the station 200 to be charged.

Specifically, the two ultrasonic generators A and B are separatelylocated at two sides of the second infrared generator C. The firstultrasonic generator A is configured to generate a first ultrasonicsignal, the second ultrasonic generator B is configured to generate asecond ultrasonic signal of which a frequency or intensity is differentfrom that of the first ultrasonic signal, and the second infraredgenerator C is configured to generate a return infrared signal that islinear.

Emission angles of the two ultrasonic generators A and B are partlyoverlapped, so that a surrounding area of the station 200 is dividedinto several sub-areas: a single signal coverage, an overlapping regionab and a middle region m. The single signal coverage includes a firstsignal coverage a that covers only the first ultrasonic signal and asecond signal coverage b that covers only the second ultrasonic signal.The overlapping region ab covers the first ultrasonic signal and thesecond ultrasonic signal.

The robotic mower 100 is provided with a first ultrasonic receiver R1, asecond ultrasonic receiver R2 and a second infrared receiver R3. In thisembodiment, the first ultrasonic receiver R1 or the second ultrasonicreceiver R2 may also be used, when in normal functionality, as thephysical boundary signal receiver 170 to receive the first boundarysignal, thereby reducing hardware costs.

The second infrared receiver R3 is located at a middle part of a frontportion of the robotic mower 100. The ultrasonic receivers R1 and R2 areseparately disposed at two sides of the second infrared receiver R3 onthe robotic mower 100.

When the robotic mower 100 needs to go back or receives a return signalfor the first time, the controller 110 controls the robotic mower 100 tofirst revolve in a circle to perform initial position judgment todetermine a sub-area to which the robotic mower 100 currently belongs.If after the robotic mower 100 revolves in a circle, the firstultrasonic receiver R1 or the second ultrasonic receiver R2 receivesonly the first ultrasonic signal, the controller 110 determines that thecurrent sub-area is the first signal coverage a. If after the roboticmower 100 revolves in a circle, the first ultrasonic receiver R1 or thesecond ultrasonic receiver R2 receives only the second ultrasonicsignal, the controller 110 determines that the current sub-area is thesecond signal coverage b. If after the robotic mower 100 revolves in acircle, the first ultrasonic receiver R1 and/or the second ultrasonicreceiver R2 receives the first ultrasonic signal and the secondultrasonic signal, the controller 110 determines that the currentsub-area is the first overlapping region ab. If after the robotic mower100 revolves in a circle, the first ultrasonic receiver R1 and/or thesecond ultrasonic receiver R2 does not receive the ultrasonic signalthat is used as the return signal, the controller 110 controls therobotic mower 100 to continue moving according to a predetermined routeor a random route.

If an initial position of the robotic mower 100 is the first signalcoverage a, the controller 110 controls the robotic mower 100 to revolveuntil only the first ultrasonic receiver R1 receives the firstultrasonic signal. As shown by a dashed part in FIG. 3, at this time, adirection of the robotic mower 100 is a moving direction, and therobotic mower 100 is controlled to enter the overlapping region ab.Similarly, when the initial position of the robotic mower 100 is thesecond signal coverage b, the controller 110 controls the robotic mower100 to revolve until only the second ultrasonic receiver R2 receives thesecond ultrasonic signal, and a direction of the robotic mower 100 atthis time is used as the moving direction.

When the robotic mower 100 enters the first overlapping region ab fromthe first signal coverage a, the first ultrasonic receiver R1 receivesthe first ultrasonic signal and the second ultrasonic signal, and thecontroller 110 controls the robotic mower 100 to revolve until the firstultrasonic receiver R1 and the second ultrasonic receiver R2 bothreceive the first ultrasonic signal and the second ultrasonic signal toenable the robotic mower 100 to face toward the station 200. Then, thecontroller 110 continues to control the robotic mower 100 to enable bothfirst ultrasonic receiver R1 and second ultrasonic receiver R2 to keepreceiving the first ultrasonic signal and the second ultrasonic signal.

An extreme case in which the robotic mower 100 is located in theoverlapping region ab is when the robotic mower 100 is located at asignal boundary of a left side of the second ultrasonic generator B. Inthis case, the controller 110 controls the robotic mower 100 to enablethe first ultrasonic receiver R1 to keep receiving the first ultrasonicsignal and the second ultrasonic receiver R2 to keep receiving thesecond ultrasonic signal. The robotic mower 100 moves forward along thesignal boundary of the left side of the second ultrasonic generator B.

Similarly, when the robotic mower 100 enters the first overlappingregion ab from the second signal coverage b, the second ultrasonicreceiver R2 receives both the first ultrasonic signal and the secondultrasonic signal, and the controller 110 controls the robotic mower 100to revolve until the first ultrasonic receiver R1 and the secondultrasonic receiver R2 both receive the first ultrasonic signal and thesecond ultrasonic signal. In this case, an extreme case is when thecontroller 110 controls the robotic mower 100 to move forward along asignal boundary of a right side of the first ultrasonic generator A.

If the initial position of the robotic mower 100 is the firstoverlapping region ab, the controller 110 still controls the roboticmower 100 to revolve until the first ultrasonic receiver R1 and thesecond ultrasonic receiver R2 both receive the first ultrasonic signaland the second ultrasonic signal.

With continued reference to FIG. 4, when the robotic mower 100 is aboutto leave the first overlapping region ab and to enter the middle regionm, if the first ultrasonic receiver R1 does not receive an ultrasonicsignal, the controller 110 controls the robotic mower 100 to revolve ina counterclockwise direction until the second infrared receiver R3receives the return infrared signal, so as to enable the robotic mower100 to face directly toward the station 200. Thereafter, the controller110 maintains a moving direction of the robotic mower 100 so thataccurate and precise connection of the robotic mower 100 and the station200 is implemented.

Similarly, when the robotic mower 100 is about to leave the firstoverlapping region ab and to enter the middle region m, if the secondultrasonic receiver R2 does not receive an ultrasonic signal, thecontroller 110 controls the robotic mower 100 to revolve in a clockwisedirection until the second infrared receiver R3 receives the returninfrared signal so as to enable the robotic mower 100 to face directlytoward the station 200.

Initial position judgment, entering area judgment and a control mannerof the robotic mower 100 within a coverage range of the generators areshown in Table 1:

TABLE 1 Signal Initial position judgment Entering area coverage (Revolvein a circle) judgment Control manner a Only a signal of A is receivedOnly a left side receives the signal of A b Only a signal of B isreceived Only a right side receives the signal of B ab Signals of A andB are Any side receives The left side and the right receivedsimultaneously the side both receive the signal of A and the signals ofA and B signal of B

To identify the first boundary signal, the first ultrasonic signal andthe second ultrasonic signal that are all ultrasonic, the first boundarysignal has a first frequency, the first ultrasonic signal has a secondfrequency, and the second ultrasonic signal has a third frequency. Thecontroller 110 stores a preset first frequency corresponding to thefirst frequency, a preset second frequency corresponding to the secondfrequency, and a preset third frequency corresponding to the thirdfrequency. If a frequency of a wireless signal received by the physicalboundary signal receiver 170 matches the preset first frequency, thecontroller 110 determines that the wireless signal is the first boundarysignal. If a frequency of a wireless signal received by the firstultrasonic receiver R1 matches the preset second frequency, thecontroller 110 determines that the wireless signal is the firstultrasonic signal. Finally, if a frequency of a wireless signal receivedby the second ultrasonic receiver R2 matches the preset third frequency,the controller 110 determines that the wireless signal is the secondultrasonic signal.

In this embodiment, at least a part of a boundary of a working area ofthe robotic mower 100 is a physical boundary. The robotic mower 100 hasa physical boundary signal generator 160, a physical boundary signalreceiver 170 and a controller 110. The physical boundary signalgenerator 160 generates a first boundary signal, and the first boundarysignal is reflected after reaching the physical boundary. After thephysical boundary signal receiver 170 receives the reflected firstboundary signal, the controller 110 determines a distance between therobotic mower 100 and the physical boundary, so as to identify theboundary. In this way, no other boundary line needs to be arranged, andcosts are relatively low.

Referring to FIG. 5, the present disclosure further provides a roboticmowing system that includes a robotic mower 100, a station 200 and aboundary apparatus. The boundary apparatus is configured to define arange of the working area. The robotic mower 100 is configured to moveand mow in the working area. The station 200 is configured to rechargethe robotic mower 100 when the robotic mower 100 is short of power andgoes back, or to provide a shelter from rain or a stop for the roboticmower 100.

Referring to FIGS. 6 and 7 at the same time, the robotic mower 100includes a housing that extends along a longitudinal direction, severalwheels 20 that are disposed at the bottom of the housing, at least onedrive motor 30 that is disposed inside the housing and is configured todrive the wheels 20, a cutting blade 42 that is disposed at the bottomof the housing and is used for cutting, a cutting motor 40 that isdisposed inside the housing and is configured to drive the cutting blade42, a power source 50 that supplies power to the drive motor 30 and thecutting motor 40.

The robotic mower 100 further includes a controller 110, a memorizer120, an operation interface and a boundary sensor 60.

The memorizer 120 stores a fixed working procedure. The operationinterface is provided with only a start button 130, a stop button 140and a power button 150. The controller 110 is connected to the memorizer120, the power source 50, the start button 130, the stop button 140, thedrive motor 30, the cutting motor 40 and the boundary sensor 60. Thepower button 150 is connected to the power source 50.

The boundary sensor 60 is configured to sense the boundary of theworking area. When the robotic mower 100 mows normally, and when theboundary sensor 60 senses the boundary, the controller 110 controls therobotic mower 100 to change its moving direction to return to theworking area. In this embodiment, the wheels 20 include a front wheel, aleft drive wheel and a right drive wheel. The drive motor 30 includes aleft drive motor and a right drive motor. The left drive motor isconfigured to drive the left drive wheel, and the right drive motor isconfigured to drive the right drive wheel. The controller 110 controlsthe left drive motor and the right drive motor to rotate at differentrotation rates, so as to cause the robotic mower 100 to change itsmoving direction to return to the working area.

When the power button 150 is pressed down, the power source 50 is turnedon or off. A start command is generated when the start button 130 ispressed down, and a stop command is generated when the stop button 140is pressed down. When receiving the start command, the controller 110executes the working procedure in the memorizer 120, so as to controlthe robotic mower 100 to automatically and repeatedly mow and return tothe station 200 to be charged, until the controller 110 receives thestop command. In another embodiment, the start button 130 and the stopbutton 140 may also be combined into one.

Referring to FIG. 8, the working procedure includes the following steps:

Step S1: Start the drive motor 30.

Step S2: Control the robotic mower 100 to enter the working area.

Step S3: Control the robotic mower 100 to mow according to apredetermined route or a random route.

Step S4: Detect at least one first parameter of the robotic mower 100.If the first parameter reaches a first predetermined value, control therobotic mower 100 to return to the station 200 to be charged. In thisembodiment, the first parameter is a working time. The controller 110starts timing when the robotic mower 100 starts. When the timing reachesa predetermined value, the controller 110 controls the robotic mower 100to return to the station 200. In another embodiment, the first parametermay also be power of the power source 50. When it is detected that thepower of the power source 50 is lower than a predetermined value, therobotic mower 100 returns to the station 200 to be charged. In thisembodiment, the power of the power source 50 is implemented by detectingvoltage of the power source 50.

Step S5: Determine whether a stop command is received in a process inwhich the robotic mower 100 mows or is recharged. If the stop command isreceived, perform step S7; otherwise, perform step S6.

Step S6: Detect at least one second parameter of the power source 50. Ifthe second parameter reaches a second predetermined value, go back tostep 51, and so forth. In this embodiment, the second parameter is powerof the power source 50, and when it is detected that the power of thepower source 50 reaches a predetermined value, go back to step 51. Inanother embodiment, the second parameter may also be a charging time.Start timing when the robotic mower 100 connects to the station 200 tobe charged, and if a predetermined time is reached, go back to step 51.

Step S7: Turn off the power source 50.

In conclusion, the controller 110 of the robotic mower 100 executes theforegoing working procedure, so that when working in a working areahaving a relatively small working area size, for example, 50 to 200square meters, the robotic mower 100 automatically and repeatedly mowsand returns to the station 200 to be charged (as long as a start commandis received) until a stop command is received. In this way, a user doesnot need to input working parameters, and costs are relatively low.

The boundary apparatus may be a physical boundary apparatus or a virtualboundary apparatus. The physical boundary apparatus is set independentlyof the robotic mower 100, and is configured to form a boundary line todefine the working area. The virtual boundary apparatus, which may bedisposed on the robotic mower 100 or outside the working area, detectssurrounding environments of the robotic mower 100, and determines,according to detected data, whether the robotic mower 100 is locatedinside the working area.

Further referring to FIG. 5, the physical boundary apparatus may be awire 310 that is electrically connected to the station 200. The wire andthe station 200 form a closed circuit to generate a magnetic signal. Theboundary sensor 60 of the robotic mower 100 is a magnetic inductiondevice that detects a boundary signal. The controller 110 determines,according to a magnetic field direction detected by a magnetic inductiondevice, whether the robotic mower 100 is located inside the workingarea.

The physical boundary apparatus may be several independent wirelessgenerators. The wireless generators are configured to generate awireless signal as the boundary signal. The boundary sensor 60 of therobotic mower 100 is a wireless receiver that detects the wirelesssignal. The controller 110 determines, according to whether the wirelessreceiver receives a wireless signal, whether the robotic mower 100 islocated inside the working area. A portable wireless generator is usedas a boundary apparatus so that the user can alter or change the workingarea quickly.

Referring to FIG. 9, in another embodiment of the robotic mowing systemof the present disclosure, the wireless generators are infraredgenerators A1, A2, A3 and A4. Infrared signals generated by the infraredgenerators A1, A2, A3 and A4 are used as the boundary line to form aclosed, or basically closed, polygonal area so as to define the workingarea of the robotic mower 100. In an embodiment, the infrared generatorsA1, A2, A3 and A4 are all located at corners of a polygon and, in thiscase, the polygonal area formed by infrared signals generated by theinfrared generators A1, A2, A3 and A4 are closed.

In this embodiment, the infrared generators A1, A2 and A3 are separatelylocated at boundary extension lines of three corners of the polygon. Thestation 200 is also located at a boundary extension line of a corner.The infrared generator A4 is disposed at a side surface facing theboundary of the station 200. In this case, the polygonal area formed byinfrared signals generated by the infrared generators A1, A2, A3 and A4is not totally closed, and a gap is formed at the station 200, whichdoes not affect implementation of the robotic mowing system of thepresent disclosure.

In this embodiment, the infrared generators A1, A2 and A3 are providedwith independent batteries or wind power generation apparatuses, so asto have independent power supplies. The infrared generator A4 is poweredby the station 200.

The wireless receivers are infrared receivers B1 and B2 that aredisposed at side surfaces of the robotic mower 100. When the infraredreceiver B1 or the infrared receiver B2 receives an infrared signal, thecontroller 110 determines that the robotic mower 100 has reached theboundary of the working area.

The virtual boundary apparatus may be a global positioning module (notshown) disposed inside the robotic mower 100, a lawn identificationmodule (also not shown), or a photographing module (also not shown)disposed outside the working area.

The global positioning module performs wireless communication with asatellite to learn a current position coordinate of the robotic mower100. The controller 110 uses a predetermined position coordinatesequence to form virtual boundary information and form a map of theworking area. If the position coordinates detected by the globalpositioning module are not inside the map surrounded by the virtualboundary information, the controller 110 determines that the roboticmower 100 is located outside the working area.

The lawn identification module is configured to determine whether acurrent position of the robotic mower 100 is a lawn according to a coloror dampness of the ground. The controller 110 determines, according towhether the robotic mower 100 is located on a lawn, whether the roboticmower 100 is located inside the working area.

Specifically, the lawn identification module may be a color sensor (notshown) that faces toward the ground, or several electrodes (also notshown) that are disposed at the bottom of the housing of the roboticmower 100. The color sensor detects a color of the ground. If the coloris green, the controller 110 determines that the robotic mower 100 islocated inside the working area. The several electrodes protrude outwardfrom the bottom of the housing. A distance between the severalelectrodes and the ground is less than a cutting height of the cuttingblade. When the robotic mower 100 is located on a lawn, grass that hasor has not been cut exists between the several electrodes. A dielectricconstant ε of the grass is far greater than a dielectric constant c ofthe air, and capacitance C between the several electrodes satisfies:C=εS/4 πkd; where S is a facing size of the several electrodes, k is aconstant, and d is a distance of the several electrodes. When theseveral electrodes are set, the facing size S and the distance d of theelectrodes are both constants, that is, change of the capacitance C isonly related to the dielectric constant ε. Whether the robotic mower 100is located on a lawn can be learned by detecting capacitance between theseveral electrodes.

The photographing module shoots the image of the robotic mower 100 andto-be-set working area, and defines a closed virtual boundary on theshot image. If it is shown on the shot image that the robotic mower 100is located outside the virtual boundary, the controller 110 determinesthat the robotic mower 100 is located outside the working area.

The robotic mower 100 further includes an obstacle detection module thatis configured to detect an obstacle. When the obstacle detection moduledetects an obstacle, the controller 110 controls the robotic mower 100to change its moving direction to avoid the obstacle.

Further referring to FIG. 6, in this embodiment, the obstacle detectionmodule is a collision sensor 15, such as a Hall sensor. The housingincludes an outer housing 12 and an inner housing 14. The outer housing12 covers the inner housing 14. The collision sensor 15 is disposedbetween the inner housing 14 and the outer housing 12. When the roboticmower 100 collides with an obstacle, the collision sensor 15 can detectrelative movement between the inner housing 14 and the outer housing 12.In another embodiment, the obstacle detection module may also be anultrasonic generator and an ultrasonic receiver. An ultrasonic signalgenerated by the ultrasonic generator is reflected by an obstacle andthen is received by the ultrasonic receiver. A distance between therobotic mower 100 and the obstacle can be calculated according to a timedifference between generating and receiving the ultrasonic signal.

The robotic mower 100 further includes a rainwater detection module thatis configured to detect rainwater. When the rainwater detection moduledetects rainwater, the controller 110 controls the robotic mower toreturn to the station. The rainwater detection module is a conductiondetection module that has one positive plate and one negative plate. Thepositive plate and the negative plate are disposed in a groove 16 at thetop of a housing 12 of the robotic mower 100. When there is water orother conductive liquid in the groove 16, the positive plate and thenegative plate are conductive, and the rainwater detection module candetect rainwater.

When the robotic mower 100 needs to return to the station 200 to becharged or for sheltering or stopping, the controller controls therobotic mower to return to the station along a boundary of the workingarea.

When the boundary apparatus is a wire, the controller 110 controls therobotic mower to cross the wire to return to the station in a clockwiseor counterclockwise direction.

Referring again to FIGS. 3 and 4, at least one ultrasonic generator isdisposed at the station 200, and the robotic mower 100 is provided withat least one ultrasonic receiver. When the robotic mower 100 goes back,the controller 110 adjusts a moving direction of the robotic mower 100according to a receiving condition of the ultrasonic receiver, so thatthe robotic mower 100 returns directly toward the station 200.

Further, specifically, a first ultrasonic generator A, a secondultrasonic generator B and an infrared generator C are disposed at thestation 200. The two ultrasonic generators A and B are separatelylocated at two sides of the infrared generator C. The first ultrasonicgenerator A is configured to generate a first ultrasonic signal, thesecond ultrasonic generator B is configured to generate a secondultrasonic signal of which a frequency or intensity is different fromthat of the first ultrasonic signal, and the infrared generator C isconfigured to generate an infrared signal that is linear.

Correspondingly, the robotic mower 100 is provided with a firstultrasonic receiver R1, a second ultrasonic receiver R2 and an infraredreceiver R3. When the robotic mower 100 goes back, the first ultrasonicgenerator A and the second ultrasonic generator B are configured toguide the robotic mower 100 to move toward the station 200. When therobotic mower 100 is close to the station 200 and receives the infraredsignal, the infrared generator C guides the robotic mower 100 to connectto the station 200 to be charged.

Referring again to FIG. 9, when the boundary apparatus is severalwireless generators A1, A2, A3 and A4, especially infrared generators,the several wireless generators A1, A2, A3 and A4 are disposed atseveral corners of the working area and have a consistent clockwise orcounterclockwise emission direction. Side surfaces of the robotic mower100 are provided with wireless receivers B1 and B2, and a front end ofthe robotic mower 100 is provided with a wireless receiver B3. Thecontroller 110 controls the robotic mower 100 to enable the wirelessreceiver B3 at the front end to keep receiving a wireless signal, so asto enable the robotic mower 100 to return to the station 200. If therobotic mower 100 reaches the boundary and the wireless receiver B1receives the wireless signal, the controller 110 controls the roboticmower 100 to revolve until the wireless receiver B3 at the front endreceives the wireless signal and the moving direction of the roboticmower 100 is maintained. When the robotic mower 100 reaches a corner andthe wireless receiver B1 receives the wireless signal again, thecontroller 110 controls the robotic mower 100 to revolve until thewireless receiver B3 at the front end receives the wireless signalagain, so that the robotic mower 100 returns to the station 200 alongthe boundary in a clockwise or counterclockwise direction. In anotherembodiment, only one side surface of the robotic mower 100 is providedwith a wireless receiver. If an emission direction of the wirelessgenerator is a consistent clockwise direction, the wireless receiver isdisposed at a left side of the robotic mower 100. If the emissiondirection of the wireless generator is a consistent counterclockwisedirection, the wireless receiver is disposed at a right side of therobotic mower 100.

It may be conceived by a person skilled in the art that a specificstructure of a robotic mower in the present disclosure may have manyvariable forms, and technical solutions that have the same or similarmain technical features with the present disclosure should all fallwithin the protection scope of the present disclosure.

What is claimed is:
 1. A robotic mowing system comprising a station anda robotic mower, wherein the robotic mower has a controller, amemorizer, a power source and a drive motor, the memorizer configured tostore a fixed working procedure and the controller configured to executethe fixed working procedure after receiving a start command input by auser so as to control the robotic mower to automatically and repeatedlymow and return to the station to be charged until the controllerreceives a stop command.
 2. The robotic mowing system according to claim1, wherein the fixed working procedure comprises: starting the drivemotor; controlling the robotic mower to enter into a predeterminedworking area; controlling the robotic mower to mow according to apredetermined route or a random route; detecting power or a dischargetime of the power source, and if the power of the power source is lowerthan a first predetermined value or the discharge time reaches a firstpredetermined time, controlling the robotic mower to return to thestation to be charged; and detecting the power or a charging time of thepower source, and if the power of the power source reaches a secondpredetermined value or the charging time reaches a second predeterminedtime, controlling the robotic mower to mow again.
 3. The robotic mowingsystem according to claim 2, wherein the robotic mowing system furthercomprises a physical boundary apparatus configured to form a boundaryline to define the predetermined working area, and the robotic mowerworking within the predetermined working area.
 4. The robotic mowingsystem according to claim 3, wherein the physical boundary apparatuscomprises independent wireless generators configured to generate awireless signal as a boundary signal, and wherein the robotic mowercomprises a wireless receiver that detects the boundary signal.
 5. Therobotic mowing system according to claim 4, wherein the wirelessgenerator comprises an infrared generator and the wireless receivercomprises an infrared receiver.
 6. The robotic mowing system accordingto claim 2, wherein the robotic mowing system further comprises avirtual boundary apparatus configured to define the predeterminedworking area of the robotic mower.
 7. The robotic mowing systemaccording to claim 6, wherein the virtual boundary apparatus comprises aglobal positioning module, a photographing module or a lawnidentification module, the global positioning module configured toperform wireless communication with a positioning satellite and form avirtual boundary by using a predetermined position coordinate sequence,the photographing module configured to shoot the robotic mower and itssurrounding area and delineate a virtual boundary on a shot image, andthe lawn identification module configured to determine whether theground is a lawn according to a color or dampness of a lawn.
 8. Therobotic mowing system according to claim 2, wherein the controllercontrols the robotic mower to return to the station along a boundary ofthe predetermined working area.
 9. The robotic mowing system accordingto claim 2, wherein the controller controls the robotic mower to returndirectly toward the station.
 10. The robotic mowing system according toclaim 9, wherein the station comprises at least one ultrasonicgenerator, the robotic mower comprises at least one ultrasonic receiver,the controller adjusts a moving direction of the robotic mower accordingto a receiving condition of the ultrasonic receiver when the roboticmower goes back, so that the robotic mower returns toward the station.11. The robotic mowing system according to claim 10, wherein the stationcomprises an ultrasonic generator and an infrared generator, the roboticmower comprises an ultrasonic receiver and an infrared receiver, theultrasonic generator and the ultrasonic receiver are configured to guidethe robotic mower to return toward the station, and the infraredgenerator and the infrared receiver are configured to guide the roboticmower to connect to the station to be charged.
 12. The robotic mowingsystem according to claim 1, wherein the robotic mower further comprisesan operation interface operable for a user, the operation interfacecomprises only a power button, a start button and a stop button, thepower button is used for turning on/off power of the robotic mower, thestart command is generated when the start button is pressed down, andthe stop command is generated when the stop button is pressed down.